Compression set packers are set a variety of ways. One way is with a hydraulic or mechanical system that creates relative movement between a mandrel and an outer assembly that drives the slips up respective cones to get a supporting bite into the surrounding tubular as well as extending a sealing assembly radially by compressing axially. Typically, the one slip is extended first and then the sealing assembly is extended followed by another slip assembly. The relative movement to set the packer is generally locked in such as with a ratcheting lock ring that prevents the relative movement from reversing to hold the set position of the components. For release the locking mechanism is defeated either with a tool run into the mandrel to shear a retainer on the locking mechanism or by cutting the mandrel with a tubular cutter to let the components relax and by doing so retract from the surrounding tubular. An upward force on the mandrel then brings the released packer out of the hole.
The act of setting the sealing assembly increases the internal pressure in the resilient components of the sealing assembly. This pressure is needed to maintain the seal against the surrounding tubular. However, while in service loads can be transmitted through the connected tubular string in either of two opposed directions. Such loading transfers into the set sealing assembly raising its internal pressure and decreasing the capacity of the sealing assembly to resist differential pressure in the two zones isolated by the sealing assembly.
The present invention addresses such loads transmitted through the tubular string in either direction and configures the mandrel and outer assembly in such a way that the load transmitted through the tubular is directed around the set sealing element to a slip assembly on the far side of the sealing element without further increasing the internal pressure in the sealing assembly. A pair of springs allow for load transfer behind the sealing assembly to a slip assembly on the far side from the direction of applied tubing load. So that an uphole force through the tubular would compress a spring located uphole of the sealing assembly and transfer such a force to the upper slips on the far side of the sealing assembly. Those skilled in the art will better appreciate these and other aspects of the present invention by a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that full scope of the invention is to be found in the appended claims.
U.S. Pat. No. 5,113,939 shows the use of a ratchet to decouple hanging weight from the sealing element and transfer such weight to a slip assembly below the sealing assembly.